It's a fierce soccer game, but it's not easy to determine what the result will be. Facing three defenders, the attacker is sprinting with the ball and leaping high, making a thrilling breakthrough.

The cheers on the field can't be heard, as the scene of the game has been frozen for thousands of years. This soccer game is "played" on a black rock in the depths of Yinshan Mountain in the Inner Mongolia autonomous region.

"This football-game rock art dates from the upper Neolithic Age to the Early Bronze Age, at least 4,000 years ago," said Zhao Zhankui, a researcher at the Hetao Cultural Museum in Bayannuur city, Inner Mongolia.

"It's impossible to verify what the ball was made of, whether there was a goal in the game or how to determine the outcome. However, from the art, we can see that this sport was very popular among our ancestors and attracted an audience."

More than 150 groups of rock art are scattered in Yinshan in Bayannuur, with more than 50,000 existing pieces of art, making the mountain one of the largest rock art collections in the world.

In this vast gallery, there are many rock art pieces showing sports scenes, giving people a more intuitive understanding of the origin of athletics.

Besides the soccer game, other rock art pieces depict running, jumping, archery, riding and other sports, as if some sort of Olympic Games were held on rocks.

On an eave-shaped boulder in the western section of Langshan Mountain, in Dengkou county, Bayannuur, a riding team charges toward the viewer through time.

Some are on horseback, some are on camels, and most of them are moving toward the left of the rock. Only two are on horseback to the right, as if they are in an equestrian competition.

In the upper right corner of the rock, a rider is supporting himself on horseback with his four limbs as if he's performing a complex gymnastics routine.

The art can help answer questions about the origin of these sports.

For example, in 2015, rock art depicting people hunting with the fur snowboards was found in Altay prefecture, Xinjiang Uygur autonomous region, dating back about 12,000 years. Altay could be one of the places where snowboarding originated.

China's sports-depicting art has drawn international attention.

Rock art in Zuojiang Huashan, located in Chongzuo, Guangxi Zhuang autonomous region, was not only China's first to be listed as a UNESCO World Heritage Site, but was also displayed during the opening ceremonies of the 2008 Summer Olympic Games in Beijing.

"Rock art is the oldest 'language' of mankind, recording ancient people's thoughts about themselves and the world. Sports are a common theme in rock art, and some mysteries about the origin of sports may be sealed in the art," said Wang Jianping, president of the China Rock Art Association.